Air heater



July 24, 1956 c. E. GOLDEN AIR HEATER Filed April 13, 1953 INVENTOR. CARL E. 604 new Ans HEATER Carl E. Golden, Burlingarne, Calih, assignor to Ransome Company, Erneryville, Calif., a corporation of California Application April 13, 1953, Serial No. 348,175

7 Claims. (Cl. 263--19) This invention relates to air heaters and particularly to an air heater especially adapted for but not restricted to drying cotton and like material.

When air heaters are installed in places where the air is laden with dirt, lint, etc., considerable difliculty in operation of such heaters has been encountered. The lint and dirt tends to clog up the burner of such a heater, and lint and other ignitable material tends to be ignited by the burner and carried by the heated air stream into ducts bound with cotton or other ignitable material, or in other places where it can do damage.

It is a main object of the present invention to provide an air heater overcoming the above difficulties and in particular an air heater including inner and outer shells so constructed and arranged and connected to a suction blower unit that air is drawn inwardly through a screen into one end of the outer shell, and passes through the space between the shells and then into and countercurrently through the inner shell, wherein a burner is disposed at the upstream end of the inner shell and has an air inlet disposed high in the space between the shells, and provision is made for introducing part of the screened air into the inner shell forwardly of the burner so that a considerable portion of the lint and dirt entrained in the screened air reaching the burner air inlet will be removed therefrom prior to the air reaching such inlet to avoid clogging the burner; to provide a heater as just described wherein provision is made for introducing unscreened air into the inner shell so as to lessen the load on the heater air screen, at a place downstream of the burner a sulficient distance so that the lint in the air will not be ignited by the burner; and to provide a heater as above described wherein there are valve means for independently controlling the flow of air through the various passages provided to thereby enable regulating the makeup and temperature of the air leaving the heater and as an incident thereto the suction within the inner and outer shells and hence the character of the flame.

Various other objects of the present invention will be apparent from the following description taken in connection with the accompanying drawings, wherein:

Fig. 1 is a vertical longitudinal mid-sectional view of a heater embodying the concepts of the present inven non.

Fig. 2 is a fragmentary sectional view taken along line 2-2 of Fig. 1.

Fig. 3 is a fragmentary end view of the lefthand end of the heater as the parts are shown in the drawings.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the heater shown is adapted to be supported in any conventional manner such as by feet or supporting posts, not shown. The heater includes an outer cylindrical shell 9 and an open ended inner cylindrical shell 11 supported concentrically within the outer cylindrical shell by radial spacers 13 fixed to the shells. A heater air inlet is provided at the lefthand end of the outer shell 9 between said lefthand and an annular flange 17 fixed to the inner 2,756,040 Patented July 24, 1955 shell and between which and the lefthand end of the outer shell there extends a cylindrical air filtering screen 19.

The righthand end of the outer shell is closed by an end plate 21, and spaced from this plate is the righthand end of inner shell 11. The lefthand end of the inner shell 11 is adapted to be connected to a suction blower unit of conventional construction, not shown, whereby circulation of air may be established from the inlet at screen 19, through the annular space between the shells, then into the righthand end of the inner shell and through the inner shell to the lefthand or outlet end thereof.

For controlling the flow of air between end plate 21 and the righthand end of inner shell 11, there is provided a cylindrical sleeve valve 23 telescopically engaging over the righthand end of the inner shell and slidably supported by the outer shell by means of radial flanges 25 secured to the inner shell 11.

Sleeve valve 23 constitutes not only a valve member but also an extension of the inner shell, and hence it is proper to say that disposed within the righthand end of the inner shell is a burner 27. Burner 27 has an air gas mixture conduit 29 extending therefrom through an elongated slot 31 provided in sleeve valve 23, said conduit terminating short of the interior of outer shell 9 at a burner air inlet 33. Fixed to and extending from conduit 29 is a gas conduit 34 extending through and fixed to outer shell 9 at 35, by which arrangement the burner is supported within the inner shell 11. An arcuate shield 37 is apertured to receive conduit 29 and is fixed to said conduit and slidably engages sleeve valve 23 so as to close slot 31 in any position of adjustment of sleeve valve 23 relative to inner shell 11.

For adjusting the position of sleeve valve 23, and thus variously restricting the space between the righthand end of inner shell 11 and plate 21, there is provided an adjustment bolt 39 secured at its lefthand end to sleeve valve 23 and extending at its righthand end through plate 21. Mounted on the righthand end of said bolt is a hand wheel 41 retained against plate 21 by a bracket 43 secured to said plate. Upon rotation of hand wheel 41 the axial position of sleeve valve 23 may be varied. More than one bolt 39 may be provided, if desired, to insure against the possibility of binding engagement between said sleeve valve and the shells.

Formed in inner shell 11 downstream of but adjacent to burner 27 are a plurality of circumferentially spaced air inlet ports 45. For controlling the passage of air through ports 45 there is provided a sleeve valve 47 telescopically engaging over inner shell 11. Secured by its lefthand end to sleeve valve 47 is an adjustment bolt 49 extending through plate 21 and provided with a hand wheel 51 held against plate 21 by a bracket 53 secured to said plate. Upon rotation of hand wheel 51 ports 45 may be variously restricted. As in the case of bolt 39, more than one bolt 49 may be provided.

Formed in the lefthand end of inner shell 11 outwardly of ilange 17 are a plurality of circumferentially spaced air inlet ports 55. Controlling the passage of air through these ports is a sleeve valve 57' encircling said inner shell and having mating ports 59 formed therein adapted to be positioned in various positions of registry with ports 55 upon circumferential adjustment of said valve sleeve. Sleeve valve 57 is precluded against axial movement by lugs 61 secured to inner shell 11. Sleeve valve 57 will remain in any position of circumferential adjustment by virtue of its frictional engagement with inner shell 11.

In operation. it is apparent that of the total quantity of air leaving the heater, only a portion directly passes burner 27, and this portion has been previously screened by screen 19 so that only a small amount of lint passes directly by burner 27. Another portion of the total quantity of air is also screened and passes through ports 45 ice and thus ahead of burner 27. The remaining portion of the total quantity of air is unscreened and passes through ports 55, thereby reducing the load imposed on screen 19. Although the air passing through ports 55 is unscreened, the lint or other ignitable material will not be ignited by burner 27 due to the remoteness of ports 55 with respect to burner 27.

It is evident from the drawings that the air drawn into ports 45 has a strong tendency to carry therewith a major portion of the lint and dirt entrained in the screened air flowing through the annular space between the shells, and thus the air reaching burner air inlet 33 is relatively free of dirt and lint. Another factor keeping dirt and lint from inlet 33 is the location of the inlet high in the outer shell.

The character of the flame issuing from burner 27 may be varied by increasing or decreasing the pressure within shell 11 by adjusting the, position of sleeve valves 23 and 47, and to a lesser extent by the adjustment of sleeve valve 57. The air passing through the annular space between the shells is preheated, and thus the temperature of the air may be regulated by adjusting sleeve valve 57 so that a greater or lesser amount of unheated air will be drawn into the stream of air flowing through shell 11.

While I have shown the preferred form of my invention, itis to be understood that various changes may be made in its construction by those skilled in the art Without departing from the spirit of the invention as defined in the appended claims.

In the claims, as well as in the specification, the terms downstream and upstream refer to the direction air is flowing in the shell, the design or construction of which is under consideration.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An air heater of the class described, comprising: an outer cylindrical shelljhaving one end closed and having at its other end a screened ambient air inlet opening; an open ended inner cylindrical shell concentrically arranged within the outer shell and having one end disposed adjacent but spaced from the closed end of the outer shell and having its other end extending outwardly of said other end of the outer shell and adapted to be connected to a suction blower unit, whereby circulation of air may be established from the ambient air inlet of the outer shell, through the annular space between the inner and outer shells, and thence into and through the inner shell; burner means arranged within said one end of said inner shell having an air inlet disposed within the annular space between the shells, said inner shell having one or more air inlet, ports formed therein adjacent said one end but downstream of said burner means, and one or more air inlet ports formed therein adjacent said other end thereof downstream of said screened ambient air inlet; and valve means for independently restricting the first and second named inlet ports and the space between said one end of said inner shell and the closed end of said outer shell.

2. An air heater, comprising an outer shell having one end closed and having at its other end an ambient air inlet opening, an open ended inner shell arranged within the outer shell and having one end disposed adjacent but spaced from the closed end of the outer shell and having its other end extending outwardly of said other end of the outer shell and adapted to be connected to a suction blower unit, whereby circulation of air may be established from the ambient air inlet of the outer shell, through the space between the inner and outer shells, and thence into and through the inner shell, burner means arranged within said one end of said inner shell having an air inlet disposed. within the space between the shells, said inner shell having one or more air inlet ports formed therein adjacent said one end but downstream of said burner means, and one or more air inlet ports formed therein adjacent said other end thereof, and valve means for independently restricting the first and second-named air inlet ports and the space between said one end of said inner shell and the closed end of said outer shell.

3. An air heater of the class described, comprising: an outer cylindrical shell having one end closed and having at its other end a screened ambient air inlet opening; an open ended inner cylindrical shell concentrically arranged within the outer shell and having one end disposed adjacent but spaced from the closed end of the outer shell and having its other end extending outwardly of said other end of the outer shell and adapted to be connected to a suction blower unit, whereby circulation of air may be established from the ambient air inlet of the outer shell, through the annular space between the inner and outer shells, and thence into and through the inner shell; burner means arranged within said one end of said inner shell having an air inlet disposed within the annular space between the shells, said inner shell having one or more air inlet ports formed therein adjacent said one end but downstream of said burner means, and one or more air inlet ports formed therein adjacent said other end thereof downstream of said screened ambient air inlet; and valve means for independently restricting the first and second named inlet ports and the space between said one end of said inner shell and the closed end of said outer shell, said valve means including a cylindrical sleeve telescopically engaging said one end of said inner shell, and means for axially adjusting said sleeve toward and away from said closed end of said outer shell to variously restrict said lastmentioned space.

4. An air heater of the class described, comprising: an outer cylindrical shell having one end closed and having at its other end a screened ambient air inlet opening; an open ended inner cylindrical shell concentrically arranged within the outer shell and having one end disposed adjacent but spaced from the closed end of the outer shell and having its other end extending outwardly of said other end of the outer shell and adapted to be connected to a suction blower unit, whereby circulation of air may be established from the ambient air inlet of the outer shell, through the annular space between the inner and outer shells, and thence into and through the inner shell; burner means arranged within said one end of said inner shell having an air inlet disposed within the annular space between the shells, said inner shell having one or more air inlet ports formed therein adjacent said one end but downstream of said burner means, and one or more air inlet ports formed therein adjacent said other end thereof downstream of said screened ambient air inlet; and valve means for independently restricting the first and second named inlet ports and the space between said one end of said inner shell and the closed end of said outer shell, said valve means including a cylindrical sleeve telescopically engaging said one end of said inner shell, and means for axially adjusting said sleeve toward and away from said closed end of said outer shell to variously restrict said last mentioned space, said valve means also including a second cylindrical sleeve telescopically engaging said inner shell adjacent the first-named inlet ports, and means for axially adjusting said second sleeve relative to said inner sleeve to variously restrict said first-named inlet ports.

5. An air heater of the class described, comprising: an outer cylindrical shell having one end closed and having at its other end a screened ambient air inlet opening; an open ended inner cylindrical shell concentrically arranged within the outer shell and having one end disposed adjacent but spaced from the closed end of the outer shell and having its other end extending outwardly of said other end of the outer shell and adapted to be connected to a suction blower unit, whereby circulation of air may be established from the ambient air inlet of the outer shell, through the annular space between the inner and outer shells, and thence into and through the inner shell; burner means arranged within said one end of said inner shell having an air inlet disposed within the annular space between the shells, said inner shell having one or more air inlet ports formed therein adjacent said one end but downstream of said burner means, and one or more air inlet ports formed therein adjacent said other end thereof downstream of said screened ambient air inlet; and valve means for independently restricting the first and second named inlet ports and the space between said one end of said inner shell and the closed end of said outer shell, said valve means including a cylindrical sleeve telescopically engaging said one end of said inner shell, and means for axially adjusting said sleeve toward and away from said closed end of said outer shell to variously restrict said lastrnentioned space, said valve means also including a second cylindrical sleeve telescopically engaging said inner shell adjacent the first-named inlet ports, and means for axially adjusting said second sleeve relative to said inner sleeve to variously restrict said first-named inlet ports, said valve means further including a third cylindrical sleeve encircling said inner shell at said other end thereof in the region where the second-named inlet ports are provided, said third cylindrical sleeve having one or more ports adapted to be variously registered with the second-named inlet ports depending on the circumferential position of the third cylindrical sleeve, to thereby control the passage of air through the second-named inlet ports.

6. An air heater of the class described, comprising: an outer cylindrical shell having one end closed and having at its other end a screened ambient air inlet opening; an open ended inner cylindrical shell concentrically arranged within the outer shell and having one end disposed adjacent but spaced from the closed end of the outer shell and having its other end extending outwardly of said other end of the outer shell and adapted to be connected to a suction blower unit, whereby circulation of air may be established from the ambient air inlet of the outer shell, through the annular space between the inner and outer shells, and thence into and through the inner shell; burner means arranged within said one end of said inner shell having an air inlet disposed within the annular space be tween the shells, said inner shell having one or more air inlet ports formed therein adjacent said one end but downstream of said burner means, and one or more air inlet ports formed therein adjacent said other end thereof downstream of said screened ambient air inlet; and valve means for independently restricting the first and second named inlet ports and the space between said one end of said inner shell and the closed end of said outer shell, said burner inlet being located in the highest part of the outer shell rearwardly of the first-named inlet ports.

7. An air heater of the class described, comprising: an

outer cylindrical shell having one end closed and having at its other end a screened ambient air inlet opening; an open ended inner cylindrical shell concentrically arranged within the outer shell and having one end disposed adjacent but spaced from the closed end of the outer shell and having its other end extending outwardly of said other end of the outer shell and adapted to be connected to a suction blower unit, whereby circulation of air may be established from the ambient air inlet of the outer shell, through the annular space between the inner and outer shells, and thence into and through the inner shell; burner means arranged within said one end of said inner shell having an air inlet disposed within the annular spacebetween the shells, said inner shell having one or more air inlet ports formed therein adjacent said one end but downstream of said burner means, and one or more air inlet ports formed therein adjacent said other end thereof downstream of said screened ambient air inlet; and valve means for in dependently restricting the first and second named inlet ports and the space between said one end of said inner shell and the closed end of said outer shell, said burner inlet being located in the highest part of the outer shell rearwardly of the first-named inlet ports, said valve means including a cylindrical sleeve telescopically engaging said one end of the inner shell and means for axially adjusting said sleeve toward and away from said closed end of said outer shell to variously restrict said last mentioned space, said valve means also including a second cylindrical sleeve telescopically engaging said inner shell adjacent the first-named inlet ports and means for axially adjusting said second sleeve to variously restrict said first-named inlet ports, said valve means further including a third cylindrical sleeve encircling said inner shell at said other end thereof in the region where the second-named inlet ports are provided, said third cylindrical sleeve having one or more ports formed therein adapted to be variously registered with the second-named inlet ports depending on the circumferential position of the third cylindrical sleeve to thereby control passage of air through the secondnamed inlet ports.

References Cited in the file of this patent UNITED STATES PATENTS 1,069,243 Fogler Aug. 5, 1913 1,301,324 Schlatter Apr. 22, 1919 2,518,364 Owen Aug. 8, 1950 2,579,614 Ray Dec. 25, 1951 

